Research ArticleCONDENSED MATTER PHYSICS

Ultrafast time-resolved x-ray scattering reveals diffusive charge order dynamics in La2–xBaxCuO4

See allHide authors and affiliations

Science Advances  16 Aug 2019:
Vol. 5, no. 8, eaax3346
DOI: 10.1126/sciadv.aax3346

Abstract

Charge order is universal among high-Tc cuprates, but its relation to superconductivity is unclear. While static order competes with superconductivity, dynamic order may be favorable and even contribute to Cooper pairing. Using time-resolved resonant soft x-ray scattering at a free-electron laser, we show that the charge order in prototypical La2−xBaxCuO4 exhibits transverse fluctuations at picosecond time scales. These sub–millielectron volt excitations propagate by Brownian-like diffusion and have an energy scale remarkably close to the superconducting Tc. At sub–millielectron volt energy scales, the dynamics are governed by universal scaling laws defined by the propagation of topological defects. Our results show that charge order in La2−xBaxCuO4 exhibits dynamics favorable to the in-plane superconducting tunneling and establish time-resolved x-rays as a means to study excitations at energy scales inaccessible to conventional scattering techniques.

This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license, which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.

View Full Text